ui: Revert gfx::BufferUsage::SCANOUT to gfx::BufferUsage::GPU_READ_WRITE change.

ui/ozone/platform/drm/gpu/gbm_buffer.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/ozone/platform/drm/gpu/gbm_buffer.h"
 
 #include <drm.h>
 #include <fcntl.h>
 #include <gbm.h>
 #include <xf86drm.h>
 
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/gfx/geometry/size_conversions.h"
 #include "ui/gfx/native_pixmap_handle_ozone.h"
 #include "ui/ozone/platform/drm/common/drm_util.h"
 #include "ui/ozone/platform/drm/gpu/drm_window.h"
 #include "ui/ozone/platform/drm/gpu/gbm_device.h"
 #include "ui/ozone/platform/drm/gpu/gbm_surface_factory.h"
 #include "ui/ozone/platform/drm/gpu/gbm_surfaceless.h"
 
 namespace ui {
 
 GbmBuffer::GbmBuffer(const scoped_refptr<GbmDevice>& gbm,
                      gbm_bo* bo,
                      gfx::BufferUsage usage)
-    : GbmBufferBase(gbm,
-                    bo,
-                    usage == gfx::BufferUsage::GPU_READ ||
-                        usage == gfx::BufferUsage::GPU_READ_WRITE),
+    : GbmBufferBase(gbm, bo, usage == gfx::BufferUsage::SCANOUT),
       usage_(usage) {}
 
 GbmBuffer::~GbmBuffer() {
   if (bo())
     gbm_bo_destroy(bo());
 }
 
 // static
 scoped_refptr<GbmBuffer> GbmBuffer::CreateBuffer(
     const scoped_refptr<GbmDevice>& gbm,
     gfx::BufferFormat format,
     const gfx::Size& size,
     gfx::BufferUsage usage) {
   TRACE_EVENT2("drm", "GbmBuffer::CreateBuffer", "device",
                gbm->device_path().value(), "size", size.ToString());
-  bool with_cpu_access =
-      usage == gfx::BufferUsage::GPU_READ_CPU_READ_WRITE ||
-      usage == gfx::BufferUsage::GPU_READ_CPU_READ_WRITE_PERSISTENT;
+  bool use_scanout = (usage == gfx::BufferUsage::SCANOUT);
   unsigned flags = 0;
   // GBM_BO_USE_SCANOUT is the hint of x-tiling.
-  if (!with_cpu_access)
+  if (use_scanout)
     flags = GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING;
   gbm_bo* bo = gbm_bo_create(gbm->device(), size.width(), size.height(),
                              GetFourCCFormatFromBufferFormat(format), flags);
   if (!bo)
     return nullptr;
 
   scoped_refptr<GbmBuffer> buffer(new GbmBuffer(gbm, bo, usage));
-  if (!with_cpu_access && !buffer->GetFramebufferId())
+  if (use_scanout && !buffer->GetFramebufferId())
     return nullptr;
 
   return buffer;
 }
 
 GbmPixmap::GbmPixmap(GbmSurfaceFactory* surface_manager)
     : surface_manager_(surface_manager) {}
 
 void GbmPixmap::Initialize(base::ScopedFD dma_buf, int dma_buf_pitch) {
   dma_buf_ = dma_buf.Pass();
@@ skipping 67 matching lines @@
       return false;
     }
   }
 
   // TODO(reveman): Add support for imported buffers. crbug.com/541558
   if (!buffer_) {
     PLOG(ERROR) << "ScheduleOverlayPlane requires a buffer.";
     return false;
   }
 
-  DCHECK(buffer_->GetUsage() == gfx::BufferUsage::GPU_READ ||
-         buffer_->GetUsage() == gfx::BufferUsage::GPU_READ_WRITE);
+  DCHECK(buffer_->GetUsage() == gfx::BufferUsage::SCANOUT);
   surface_manager_->GetSurface(widget)->QueueOverlayPlane(OverlayPlane(
       buffer_, plane_z_order, plane_transform, display_bounds, crop_rect));
   return true;
 }
 
 bool GbmPixmap::ShouldApplyScaling(const gfx::Rect& display_bounds,
                                    const gfx::RectF& crop_rect,
                                    gfx::Size* required_size) {
   if (crop_rect.width() == 0 || crop_rect.height() == 0) {
     PLOG(ERROR) << "ShouldApplyScaling passed zero scaling target.";
     return false;
   }
 
   if (!buffer_) {
     PLOG(ERROR) << "ShouldApplyScaling requires a buffer.";
     return false;
   }
 
   gfx::Size pixmap_size = buffer_->GetSize();
   // If the required size is not integer-sized, round it to the next integer.
   *required_size = gfx::ToCeiledSize(
       gfx::SizeF(display_bounds.width() / crop_rect.width(),
                  display_bounds.height() / crop_rect.height()));
   return pixmap_size != *required_size;
 }
 
 }  // namespace ui